1. Technical Field
The present disclosure relates to a printed circuit board (PCB).
2. Description of Related Art
Nowadays, some PCBs, such as computer motherboards, include analog audio input/output (I/O) ports, such as those for a microphone and speaker. The analog audio I/O ports are connected to an audio chip through some audio traces in the PCBs, however, these audio traces easily pick up noise signals from other circuits or reference layers of the PCBs. Furthermore, if the I/O ports are antennas, the noise signals can be emitted through the I/O ports, which can produce electro magnetic interference (EMI) problems.